Recently, as robot industries are rapidly grown and research thereon is supported all over the world, intelligent robots for services, industries and special purposes are being actively developed. In addition, intensive research is being carried out on functions and motions of robots to provide various high-quality services. Especially, sensing systems, communication and network technologies, various motions, and functions for overcoming obstacles and extreme topographies are added to exploring, observing, and guarding robots to perform their functions at intended positions, thereby functioning as high performance robots that obtain reliable information and expand their fields.
Typically, two-wheel mobile robots have simpler motion mechanisms, higher speed, and are more economical than biped robots and moving robots having special shapes, but the two-wheel mobile robots have limitations in movements on special topographies. Thus, research is carried out on biped robots that have excellent mobility on special topographies, multi-wheel robots, and robots including driving devices having special shapes. However, two-wheel mobile robots or two-wheel service robots can be manufactured at lower costs than typical humanoid robots and various mobile robots, and furthermore, have excellent mobility for simple mechanisms.
A two-wheel mobile robot 1 as described above is illustrated in FIG. 1. Unlike a typical USN sensor node, the two-wheel mobile robot 1 is a movable small intelligent robot that can communicate while on a move, and transmit various types of information at an intended position in real time. The two-wheel mobile robot 1 includes wheels 20a and 20b at both sides of a main body 10, and uses a wireless communication between the small mobile robot 100 and a personal digital assistant (PDA) 30 using Bluetooth, to check and adjust movements (such as forward and rearward movements and a rotation)/stop of the two-wheel mobile robot 1, and monitoring of camera image information, on a control window of a screen of the PDA 30. Furthermore, a speed of a direct current (DC) motor can be adjusted to control a movement speed of the two-wheel mobile robot 1 and sense information from various sensors. In addition, when the two-wheel mobile robot 1 includes a remote controller 40 that has buttons for movements (such as forward and rearward movements and a rotation)/stop of the two-wheel mobile robot 1 and a button for adjusting a speed of the two-wheel mobile robot 1, the two-wheel mobile robot 1 can move within a narrow space and make an easy detour around an obstacle.
A typical USN system requires a number of sensor node systems to obtain accurate and stable environmental information in a wide region. However, the two-wheel mobile robot 1 can communicate with another robot and move to expand an environmental region to be sensed, and can maximally approach an intended position to accurately measure a target value to be sensed.
The two-wheel mobile robot 1 uses a gyro sensor, an acceleration sensor, and an encoder to sense torque generated by an inclination and inertia, and constitutes a feedback compensation circuit to maintain and balance a posture, thereby efficiently moving a system and controlling motions. The two-wheel mobile robot 1 further includes a sensor for sensing an obstacle and an object to sense front and rear conditions in real time and provide information for a detour.
In addition, the two-wheel mobile robot 1 includes an integral module for an image and a communication to miniaturize a system, and the integral module communicates with another robot and a server, and further, can transmit and receive position information while the two-wheel mobile robot 1 moves. However, when the two-wheel mobile robot 1 having high performances as described above meets a distinctive topography, particularly, a stepped topography such as a threshold while moving to a sensed target point, the wheels 20a and 20b may be pushed back by the stepped topography without going over it. Thus, since the two-wheel mobile robot 1 is pushed back without overcoming the stepped topography, the two-wheel mobile robot 1 may not arrive at the target point.